In the production of optical components, recording media, semiconductor devices, etc., as a method for forming a fine pattern in a short time, a method for forming a fine pattern on the surface of a substrate (nanoimprinting method) is known wherein a mold having on its surface a reverse pattern of such a fine pattern, is pressed to a photocurable composition placed on the surface of a substrate, and the photocurable composition is irradiated with light to cure the photocurable composition thereby to form a fine pattern on the surface of the substrate (Patent Documents 1 and 2).
However, in such a method, the cured product of the photocurable composition adheres to the mold, whereby it is difficult to separate the cured product from the mold. Therefore, it is necessary to apply a release agent to the surface of the mold. However, it becomes difficult to precisely transfer the reverse pattern of the mold due to the film thickness of the release agent itself, the fluctuation in application of the release agent, etc.
The following one has been proposed as a photocurable composition capable of forming a cured product having a good release property.
(1) A photocurable composition comprising a fluorinated monomer, a monomer containing no fluorine, a fluorinated surfactant or fluorinated polymer, and a polymerization initiator (Patent Document 3).
Meanwhile, in an application to an optical component (such as a lens array or a photonic crystal), the refractive index may sometimes be required to be at least 1.54. However, the photocurable composition of (1) contains a fluoromonomer having a low refractive index, whereby it is difficult to obtain a cured product which has a high refractive index and a good release property.